October 23, 2012
Dominican Players and Plate Discipline: Additional Data
If you read Jorge Arangure Jr.’s great guest piece on Dominican players and plate discipline today, you may have wondered, as I did, whether we could see any difference between Dominicans and non-Dominicans in the data. Jorge mentioned how few Dominicans are among their respective leagues’ leaders in walk rate, but I wanted to see how DR-born players stacked up as a group. I asked BP data dude Dan Turkenkopf to run the numbers, and this is what he found for major leaguers in 2012. (Note: pitcher hitting is included, and the “league” rates include Dominican players.)
Major leaguers born in the Dominican Republic did swing and chase slightly more often and walk slightly less often in 2012 (which doesn’t mean they were worse hitters overall). Of course, there could be some selection bias here, since Dominican players with worse plate discipline than Angel Berroa would be weeded out before they make the majors. We don’t have plate discipline stats for minor leaguers, but we can check their unintentional walk rates:
The differences in walk rate are more pronounced in the minors, though the gaps don’t grow at the lower levels—we see the biggest separation at Triple-A, at least this season.
Something else it’s important to note: some players in the “Dominican” group were born in the Dominican Republic but played in the United States as amateurs and were drafted, not signed as international free agents. These players—including Albert Pujols and Jose Bautista—didn’t receive the same sort of swing-happy instruction Jorge wrote about, so we checked to make sure that they weren't skewing the results. Take those players out, and we see some slight changes in the Dominican-born (and Dominican-raised) group at the major-league level: swing rate rises from 47.4 percent to 47.8 percent, O_Swing rate rises from 31.3 percent to 31.7 percent, and walk rate falls from 7.0 percent to 6.8 percent. As expected, the Dominican-born, U.S.-raised players in the sample weren't saddled with the same impatient approach.
Thanks to Dan Turkenkopf and Colin Wyers for research assistance.